46 THE VOYAGE OF THE CH-^LLENGER. 



fragments cemented together by a calcareous paste, the result of the 

 complete disintegration of many of them, and beneath this a nearly 

 uniform calcareous paste, coloured grey by decomposed oi-ganic matter, 

 and containing whole and fragmentary shells only sparsely scattered 

 thi-ough it (pp. 20C-7, vol. I.) Mr. Murray, one of the naturalists of the 

 expedition, paid great attention to the question of the origin of this 

 calcareous formation. Very early in the vojage he formed the opinion 

 that all the organisms entering into its composition at the bottom are 

 dead, and that all of them live abundantly at the surface and at inter- 

 mediate depths over the globigerina-ooze area, the ooze being formed by 

 the siibsiding of these shells to the bottom after death (p. 208, 

 vol. I.) This, although not a new view, was a disputed one, Dr. 

 (Jarpeuter and Sir "\Yj"ville Thomson being formerly among those who 

 thought that the e\'idence was conclusive that the foramiuifera which 

 formed the globigerina-ooze lived on the bottom. Sir "VVj-Adlle (p. 210, 

 vol. I.) now acknowledges that he was mistaken, and he is of opinion 

 that it may "be taken as proved that all the matei'ials of such deposits 

 (\vith the exception, of course, of the remains of animals, which we now 

 know to live at the bottom at all depths, and which occur in the deposit 

 as foreign bodies) are derived from the surface." " Mr. Mun'ay finds the 

 closest relation to exist between the surface fauna of any particular 

 locahty and the deposit which is taking place at the bottom." 



The voyage has made known to us a number of new and beautiful 

 forms of Sponges. One of these, EuplectcUa suberea, a beautiful and 

 singular addition to these forms of European fauna, is figured at page 

 139, vol. I. It belongs to a very special group of sponges called the 

 Hexactinellid.e, because tlie siliceous spicules throughout the family 

 appear to be six-rayed. It is an old familj' abounding in many graceful 

 shapes in the beds of chalk and greensand of the south of England, biit 

 until lately the fossil " ventriculites " were supposed to be extinct, and the 

 discovery of their descendants living in the modem chalk beds of the 

 Atlantic was one of the most interesting of the many coiToborative 

 evidences in favour of the view of the " continuity of the chalk." 



The expedition has much enlarged our knowledge of deep sea fauna. 

 It has introduced us not only to new sponge forms but to numbers of new 

 criistaceans, corals, sea urchins, star fishes, bryozoa, and fishes. The 

 observations on the " Gulf-streum " and the fauna of the "gulf weed" 

 ( Sargassutii hacciferum) are particularly interesting. 



During such a protracted voyage opportunities for landing on shore 

 were always gladly made use of, and some of the descriptions of what 

 was seen on these occasions will, we have no doubt, be among the most 

 attractive portions of the narrative to general readex's. We may point 

 out the description of the BeiTnudas Islands, and the formation and 

 characteristic peculiarities of coral reefs as a good specimen of Sir 

 Wyville's descriptive powers. The geology of the Bermudas is sketched 

 slightly, but with mucli precision. Some curious particulars are given of 

 a " Sand-glacier" at Elbow Bay, on the southern shore of the main island. 

 Tlie sand has entirely filled up a valley, and is steadily progressing inland 

 in a mass five and twenty feet thick. It is covering up cottages, and has 

 ovei-whelmed a cedar wood. The only way of stopping it artificially, says 

 our author, is to cover it witli vegetation. If planted in large numbers and 

 tended and watered for a time it seems that oleanders and the native 

 juniper will grow in the pure sand, and if they once take root the motion 

 of the sand ceases. Some native i>lants, wliicli form a peculiar vegeta- 

 tion, sending out enormously long runners or roots — such as Jpom<ra pes- 

 ciiprtv and Corrnlnhn vvifcra, and the crabgi-ass Agrostis vii-f/inica — then 

 take hold of it and it becomes permanently fixed. The outer aspect of 

 the sandhill of course slopes downwards towards the sea, and whenever 



